One type of passenger entertainment network is described in U.S. Pat. No. 4,866,515, issued Sep. 12, 1989 (assigned to Sony Corporation). In this network, a central station includes video and audio signal sources and ROMs (read-only-memories) which contain stored computer software such as game software. User terminals, mounted at seats of a multi-passenger vehicle (or seats of a stadium, or the like), are connected to the central station by a network. Video signals, audio signals, and/or computer software data are transmitted over the network from the central station, and are selectively received by individual ones of the user terminals. For example, ROM 9b in the central station can download software for playing a computer game to user terminal 35 over the network, and the software received at the user terminal can be stored in the memory of a microprocessor 37 connected thereto and executed by the personal computer (e.g., so that a user can play a computer game by entering commands from input device 35e at the user terminal to the microprocessor 37). Alternatively, the patent teaches that microprocessor 37 at the user terminal can include a ROM (not shown in the drawings) and can execute software that has been prestored in such ROM. Each user terminal includes a display device 35a for displaying video from the central station (or other images such as computer graphics produced by software downloaded from the central station) and headphones 35c for playing audio from the central station.
Due to the large amount of data (including computer software data) which must be transmitted from the central station to the user terminals in a network of the type described in U.S. Pat. No. 4,866,515, such a network must be implemented in relatively expensive manner to be capable of transmitting the data with high bandwidth. In particular, the network of U.S. Pat. No. 4,866,515 must employ apparatus for transmitting and receiving frequency-multiplexed signals through a leaky cable 21 which connects the user terminals and the central station. The relatively high bandwidth requirements of such a conventional network would be even higher if the system were modified to support transmission of interactive multimedia software and related data between the central station and the user terminals.
It would be desirable to implement an entertainment or information network (of the type that can be installed in passenger vehicle or the like) to provide multiple user terminals with interactive multimedia software (and other interactive applications software) as well as video and audio, with substantially reduced network bandwidth requirements. The invention achieves this objective by providing a means for interfacing a CD-ROM player (at each user terminal) to such a network.